In the last decade, IGCC (Integrated Gasification Combined Cycle) technology has come into use for electrical power generation. It is characterized in that the fuel is not combusted directly, but first undergoes a gasification process using oxygen or air to produce a combustion gas rich in hydrogen and carbon monoxide. Said combustion gas can then be used in a combined cycle gas and steam turbine process. A number of such plants have been built worldwide, with in particular hard coals and petroleum cokes being used a fuels. The relevant background art is extensively described in the international technical literature.
Reference shall be made here to the following publications:    Trevino, M: Integrated Gasification Combined Cycle Technology; IGCC, ELCOGAS, Club Español de la Energia, March 2003    Gomez, F. S. et al.: Puertollano IGCC Plant: Operating Experiences and Further Technology Development for Commercial Generation of Clean Energy from Coal Russia Power Conference 2004, 10-11, Mar. 2004, Moscow    Delaney, R.: Hatfield—The first United Kingdom IGCC Plant IChemE Conference “Gasification—A versatile solution” 10-12 May 2004 Brighton, UK
The advantage of IGCC technology is that, by combining a gas turbine, with its high inlet temperatures, with a downstream steam turbine which uses the gas turbine's waste heat steam, increased efficiencies can be achieved. In addition, there are developments to modify IGCC technology such that a concentrated CO2 stream is obtained which creates the necessary conditions for separating off the CO2 and removing it from the atmosphere e.g. by means of underground storage. The first demonstration power plants are in preparation. Descriptions of the technology can be found in:    Denkhahn, W. et al.: Wege zum CO2—emissionsfreien fossilbefeuerten Kraftwerk (Towards a CO2 emissions-free fossil-fired power plant) Energiewirtschaftliche Tagesfragen ½. 2004, pages 86-89    Higginbotham, P “Process Integration in Gasification et al.: System for Multiproduct Applications” in 6th European Gasification Conference, 10-12 May 2004, Brighton, UK.
IGCC technology with CO2 capture is characterized by the following process stages:
gasification of the fuel, e.g. in an entrained bed gasifier at temperatures of between 1250 and 1700° C.
cooling of the gasification gas and saturation with water vapor at 190-220° C.
raw gas conversion by carrying out the reactionCO+H2OCO2+H2 
removal of carbon dioxide and sulfur compounds from the converted raw gas using prior art methods
conversion of the resulting technical hydrogen into electricity in a combined cycle (gas and steam turbine) process
compressing the abstracted carbon dioxide and taking it away for storage underground
Said prior art is characterized by the following disadvantages:                The efficiency of IGCC technology with CO2 capture is up to 10% less than that without CO2 capture. In addition to the energy required for CO2 compression, which is an inherent feature of all the technology models, this disadvantage results from the stages of CO conversion and CO2 separation from the converted raw gas.        
CO conversion is strongly exothermic, which means that some of the chemical energy contained in the raw gas is converted into heat and can only be used for steam generation.                CO2 capture cannot be performed selectively but only collectively with the sulfur compounds. These components therefore have to be separated out in a secondary stage. The energy required for regenerating the solvent used for absorption is very high, resulting in considerable steam consumption.        